DC/OS has two categories of operations for managing multiple clusters:

Cluster connection - operations allow you to set up connections, authenticate, and attach to clusters to enable access to the cluster from the CLI.

Cluster link - operations allow you to create and remove links between clusters. Once you have authenticated to a cluster, in the CLI you can seamlessly attach to a linked cluster without having to repeat the connection and authentication steps. In the UI if the clusters share an SSO provider you can easily switch between linked clusters.